Quelle  pg_largeobject.h

/*-------------------------------------------------------------------------
 *
 * pg_largeobject.h
 *   definition of the "large object" system catalog (pg_largeobject)
 *
 *
 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/catalog/pg_largeobject.h
 *
 * NOTES
 *   The Catalog.pm module reads this file and derives schema
 *   information.
 *
 *-------------------------------------------------------------------------
 */
#ifndef PG_LARGEOBJECT_H
#define PG_LARGEOBJECT_H

#include "catalog/genbki.h"
#include "catalog/pg_largeobject_d.h" /* IWYU pragma: export */
#include "utils/snapshot.h"

/* ----------------
 *  pg_largeobject definition.  cpp turns this into
 *  typedef struct FormData_pg_largeobject
 * ----------------
 */
CATALOG(pg_largeobject,2613,LargeObjectRelationId)
{
 Oid   loid BKI_LOOKUP(pg_largeobject_metadata); /* Identifier of large
 * object */
 int32  pageno;   /* Page number (starting from 0) */

 /* data has variable length, but we allow direct access; see inv_api.c */
 bytea  data BKI_FORCE_NOT_NULL; /* Data for page (may be
 * zero-length) */
} FormData_pg_largeobject;

/* ----------------
 *  Form_pg_largeobject corresponds to a pointer to a tuple with
 *  the format of pg_largeobject relation.
 * ----------------
 */
typedef FormData_pg_largeobject *Form_pg_largeobject;

DECLARE_UNIQUE_INDEX_PKEY(pg_largeobject_loid_pn_index, 2683, LargeObjectLOidPNIndexId, pg_largeobject, btree(loid oid_ops, pageno int4_ops));

extern Oid LargeObjectCreate(Oid loid);
extern void LargeObjectDrop(Oid loid);
extern bool LargeObjectExists(Oid loid);
extern bool LargeObjectExistsWithSnapshot(Oid loid, Snapshot snapshot);

#endif       /* PG_LARGEOBJECT_H */